Refueling operations using a flying boom, or simply boom, require that the tip of the tube, which is in its interior and which dispenses the fuel (called dispensing nozzle), be inserted in a receptacle mounted on the upper surface of the receiver aircraft, wherein the fuel receiver mouth is located. Once contact has been established, which consists of introducing said boom tube tip nozzle, of the tanker aircraft, into the mouth of the receptacle of the receiver aircraft, the fuel will be supplied (after engaging with the receiver's receptacle by means of contactor hooks attached to said nozzle).
The major advantage of boom refueling is, on the one hand, the higher transfer rate achieved (and, thus, shorter refueling time) and, on the other, the workload of the receiver aircraft's pilot, which is smaller than in the case of probe-and-drogue, where the pilot is directly responsible for the operation. In the latter probe-and-drogue method, the receiver aircraft's pilot is almost exclusively responsible for establishing contact.
The operation with a boom is less stressful for the receiver aircraft's pilot, which merely consists of being in an adequate position with respect to the tanker aircraft. Performing the aforementioned operation with a boom requires knowing, at any given time, the positions of both the tube tip (i.e. of the nozzle) and of the receptacle mouth. Said information is currently acquired visually by the operator in charge of manually performing the contact operation (“Boomer”).
In order to automate the operation, this information must be supplied to the system of the tanker that controls the boom in order for it to modify the relevant “control laws” that control its motion. It can also be supplied for the tanker control and even for the receiver control. In this manner, the three can contribute to a convenient and safe automated operation. This operation is currently performed manually.
In-flight aerial refueling is currently performed in two different ways: with a probe-and-drogue or with a flying boom. In the case of the boom, the tip or nozzle (fuel outlet nozzle) of its tube must be inserted in a receptacle disposed on the surface of the aircraft that will be receiving the fuel. This entire operation is currently performed manually and depends on the expertise of the tanker operator or “Boomer”.
In order to have accurate information of both points (tube tip and receptacle mouth), signaling devices and sensors capable of “seeing” those signals are normally used to determine the positions of both.
The following patents related to the object of the invention are known in the state of the art.
U.S. Pat. No. 6,752,357 describes a system for measuring the distance from a refueling aircraft comprising at least one telescoping refueling boom, at least one receptacle and a computer. The refueling tube is equipped with a nozzle. The geometry of the tube nozzle is suitable for connecting to an aircraft refueling receptacle. Each camera forms a plurality of images, both of the tube nozzle and of the refueling receptacle. The computer receives each of the images, converts the images to a plurality of pixels and analyses the images to determine a distance between the boom nozzle and the refueling receptacle. The tip of the refueling boom constitutes a fixed reference point between the mating end and the refueling aircraft. The fixation point of the aircraft's camera also forms a reference point of the camera.
U.S. Pat. No. 5,530,650 discloses a visual guidance system and a method, which includes a subsystem that locates both the structures of the aircraft and the mating structures thereof and also determines their motion and their rate of change of motion. The locating subsystem has an electrical output which feeds the location and motion data to a guidance system computer which uses software that combines the data with other data in a database containing the dimensional size and configuration of the aircraft and mating structures. The combined data are converted to a suitable format and fed to the computer monitor that displays the aircraft and mating structures thereof in real time during the refueling operation. The computer monitor has image controls which allow the operator to select the perspective viewing angle and image contrast and color in order to enhance the visual signals provided by the image to facilitate the refueling operation.
US2007023575: This patent discloses a viewing system for use in an in-flight aerial refueling tanker that does not require multiple cameras to provide a stereo image so that a boom operator may perform a refueling operation in a receiver vehicle.
US20110147528: This patent discloses a three-dimensional system for viewing a given scenario, making it possible to view different parts of the scenario in greater detail. It also seeks to provide viewing methods and systems for tanker aircraft to monitor receiver aircraft refueling operations, which enable viewing of selected zones of the refueling area in greater detail. The system comprises at least two high-resolution cameras for providing video signals of said scenario for stereo monitoring, at least one three-dimensional monitoring system for displaying three-dimensional images of said scenario and also comprises means for viewing zoomed three-dimensional images of a selected zone of the scenario.
U.S. Pat. No. 7,469,863: This patent discloses an automated refueling system and the associated methods, which has an input device for an operator, configured to receive inputs, and a first input signal corresponding to a position for an in-flight aerial refueling device. It also has a sensor positioned to detect the location of at least one of the refueling devices.